Generate RN specific Files in RN (#47458)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/47458

We are in a weird situation where React Native depends on some files that are generated by Codegen.

Codegen runs in the user project, so those dependencies are not available to React Native if we try to build it in isolation.

This is a problem and a blocker to prepare the prebuilds for iOS.

This image show the changes we are introducing:
On the right we have the current situation.
On the left the new one.

{F1954418630}

## Changelog:
[Internal] - Generate React Native specific code inside React Native

Reviewed By: cortinico, blakef

Differential Revision: D65541505

fbshipit-source-id: 1412d7f23c4d2230b795af41f1e832c8a70d5859

.gitignore

@@ -124,7 +124,7 @@ vendor/
 !/packages/rn-tester/Pods/__offline_mirrors_jsc__
 
 # @react-native/codegen
-/packages/react-native/React/FBReactNativeSpec/FBReactNativeSpec
+/packages/react-native/React/FBReactNativeSpec/
 /packages/react-native-codegen/lib
 /packages/react-native-codegen/tmp/
 /packages/react-native/ReactCommon/react/renderer/components/rncore/

packages/react-native/Libraries/AppDelegate/React-RCTAppDelegate.podspec

@@ -74,7 +74,7 @@ Pod::Spec.new do |s|
   s.dependency "React-RCTImage"
   s.dependency "React-CoreModules"
   s.dependency "React-nativeconfig"
-  s.dependency "ReactCodegen"
+  s.dependency "React-RCTFBReactNativeSpec"
   s.dependency "React-defaultsnativemodule"
 
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])

packages/react-native/Libraries/Blob/React-RCTBlob.podspec

@@ -57,7 +57,7 @@ Pod::Spec.new do |s|
   s.dependency "React-Core/RCTWebSocket"
   s.dependency "React-RCTNetwork"
 
-  add_dependency(s, "ReactCodegen")
+  add_dependency(s, "React-RCTFBReactNativeSpec")
   add_dependency(s, "React-NativeModulesApple")
   add_dependency(s, "React-jsinspector", :framework_name => 'jsinspector_modern')
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])

packages/react-native/Libraries/Image/React-RCTImage.podspec

@@ -53,7 +53,7 @@ Pod::Spec.new do |s|
   s.dependency "React-Core/RCTImageHeaders"
   s.dependency "React-RCTNetwork"
 
-  add_dependency(s, "ReactCodegen")
+  add_dependency(s, "React-RCTFBReactNativeSpec")
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])
   add_dependency(s, "React-NativeModulesApple")
 

packages/react-native/Libraries/LinkingIOS/React-RCTLinking.podspec

@@ -50,7 +50,7 @@ Pod::Spec.new do |s|
   s.dependency "ReactCommon/turbomodule/core", version
   s.dependency "React-jsi", version
 
-  add_dependency(s, "ReactCodegen", :additional_framework_paths => ["build/generated/ios"])
+  add_dependency(s, "React-RCTFBReactNativeSpec")
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])
   add_dependency(s, "React-NativeModulesApple", :additional_framework_paths => ["build/generated/ios"])
 end

packages/react-native/Libraries/NativeAnimation/React-RCTAnimation.podspec

@@ -50,7 +50,7 @@ Pod::Spec.new do |s|
   s.dependency "React-jsi"
   s.dependency "React-Core/RCTAnimationHeaders"
 
-  add_dependency(s, "ReactCodegen", :additional_framework_paths => ["build/generated/ios"])
+  add_dependency(s, "React-RCTFBReactNativeSpec")
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])
   add_dependency(s, "React-NativeModulesApple")
 end

packages/react-native/Libraries/Network/React-RCTNetwork.podspec

@@ -50,7 +50,7 @@ Pod::Spec.new do |s|
   s.dependency "React-jsi"
   s.dependency "React-Core/RCTNetworkHeaders"
 
-  add_dependency(s, "ReactCodegen", :additional_framework_paths => ["build/generated/ios"])
+  add_dependency(s, "React-RCTFBReactNativeSpec")
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])
   add_dependency(s, "React-NativeModulesApple", :additional_framework_paths => ["build/generated/ios"])
 end

packages/react-native/Libraries/PushNotificationIOS/React-RCTPushNotification.podspec

@@ -50,7 +50,7 @@ Pod::Spec.new do |s|
   s.dependency "React-Core/RCTPushNotificationHeaders"
   s.dependency "React-jsi"
 
-  add_dependency(s, "ReactCodegen", :additional_framework_paths => ["build/generated/ios"])
+  add_dependency(s, "React-RCTFBReactNativeSpec")
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])
   add_dependency(s, "React-NativeModulesApple")
 end

packages/react-native/Libraries/Settings/React-RCTSettings.podspec

@@ -50,7 +50,7 @@ Pod::Spec.new do |s|
   s.dependency "React-jsi"
   s.dependency "React-Core/RCTSettingsHeaders"
 
-  add_dependency(s, "ReactCodegen", :additional_framework_paths => ["build/generated/ios"])
+  add_dependency(s, "React-RCTFBReactNativeSpec")
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])
   add_dependency(s, "React-NativeModulesApple", :additional_framework_paths => ["build/generated/ios"])
 end

packages/react-native/Libraries/Vibration/React-RCTVibration.podspec

@@ -50,7 +50,7 @@ Pod::Spec.new do |s|
   s.dependency "React-jsi"
   s.dependency "React-Core/RCTVibrationHeaders"
 
-  add_dependency(s, "ReactCodegen", :additional_framework_paths => ["build/generated/ios"])
+  add_dependency(s, "React-RCTFBReactNativeSpec")
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])
   add_dependency(s, "React-NativeModulesApple")
 end

packages/react-native/React/CoreModules/React-CoreModules.podspec

@@ -71,7 +71,7 @@ Pod::Spec.new do |s|
   s.dependency "SocketRocket", socket_rocket_version
   add_dependency(s, "React-jsinspector", :framework_name => 'jsinspector_modern')
 
-  add_dependency(s, "ReactCodegen")
+  add_dependency(s, "React-RCTFBReactNativeSpec")
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])
   add_dependency(s, "React-NativeModulesApple")
 end

packages/react-native/React/React-RCTFBReactNativeSpec.podspec

@@ -0,0 +1,84 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+require "json"
+
+package = JSON.parse(File.read(File.join(__dir__, "..", "package.json")))
+version = package['version']
+
+source = { :git => 'https://github.com/facebook/react-native.git' }
+if version == '1000.0.0'
+  # This is an unpublished version, use the latest commit hash of the react-native repo, which we’re presumably in.
+  source[:commit] = `git rev-parse HEAD`.strip if system("git rev-parse --git-dir > /dev/null 2>&1")
+else
+  source[:tag] = "v#{version}"
+end
+
+module_name = "FBReactNativeSpec"
+header_dir = "FBReactNativeSpec"
+
+folly_config = get_folly_config()
+folly_compiler_flags = folly_config[:compiler_flags]
+folly_version = folly_config[:version]
+boost_config = get_boost_config()
+boost_compiler_flags = boost_config[:compiler_flags]
+new_arch_flags = ENV['RCT_NEW_ARCH_ENABLED'] == '1' ? ' -DRCT_NEW_ARCH_ENABLED=1' : ''
+
+header_search_paths = [
+  "\"$(PODS_ROOT)/RCT-Folly\"",
+]
+
+Pod::Spec.new do |s|
+  s.name                   = "React-RCTFBReactNativeSpec"
+  s.version                = version
+  s.summary                = "FBReactNativeSpec for React Native."
+  s.homepage               = "https://reactnative.dev/"
+  s.license                = package["license"]
+  s.author                 = "Meta Platforms, Inc. and its affiliates"
+  s.platforms              = min_supported_versions
+  s.source                 = source
+  s.source_files           = "FBReactNativeSpec/**/*.{c,h,m,mm,S,cpp}"
+  s.compiler_flags         = folly_compiler_flags + ' ' + boost_compiler_flags + new_arch_flags
+  s.header_dir             = header_dir
+  s.module_name            = module_name
+  s.pod_target_xcconfig    = {
+    "HEADER_SEARCH_PATHS" => header_search_paths,
+    "OTHER_CFLAGS" => "$(inherited) " + folly_compiler_flags + new_arch_flags,
+    "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard()
+  }
+
+  s.dependency "React-jsi"
+  s.dependency "React-jsiexecutor"
+  s.dependency "RCT-Folly"
+  s.dependency "RCTRequired"
+  s.dependency "RCTTypeSafety"
+  s.dependency "React-Core"
+  s.dependency "React-NativeModulesApple"
+  add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])
+  add_dependency(s, "ReactCommon", :subspec => "turbomodule/bridging", :additional_framework_paths => ["react/nativemodule/bridging"])
+
+  if ENV["USE_HERMES"] == nil || ENV["USE_HERMES"] == "1"
+    s.dependency "hermes-engine"
+  else
+    s.dependency "React-jsc"
+  end
+
+
+  s.script_phases = [
+    {
+      :name => '[RN]Check FBReactNativeSpec',
+      :execution_position => :before_compile,
+      :script => <<-EOS
+echo "Checking whether Codegen has run..."
+fbReactNativeSpecPath="$REACT_NATIVE_PATH/React/FBReactNativeSpec"
+
+if [[ ! -d "$fbReactNativeSpecPath" ]]; then
+  echo 'error: Codegen did not run properly in your project. Please reinstall cocoapods with `bundle exec pod install`.'
+  exit 1
+fi
+      EOS
+    }
+  ]
+end

packages/react-native/ReactCommon/React-FabricComponents.podspec

@@ -92,7 +92,7 @@ Pod::Spec.new do |s|
     "react/renderer/components/view/platform/cxx",
     "react/renderer/imagemanager/platform/ios"
   ])
-  add_dependency(s, "ReactCodegen", :additional_framework_paths => ["build/generated/ios"])
+  # add_dependency(s, "React-RCTFBReactNativeSpec")
 
   if ENV["USE_HERMES"] == nil || ENV["USE_HERMES"] == "1"
     s.dependency "hermes-engine"

packages/react-native/ReactCommon/jsi/React-jsi.podspec

@@ -38,8 +38,11 @@ Pod::Spec.new do |s|
 
   s.header_dir    = "jsi"
   s.compiler_flags         = folly_compiler_flags + ' ' + boost_compiler_flags
-  s.pod_target_xcconfig    = { "HEADER_SEARCH_PATHS" => "\"$(PODS_ROOT)/boost\" \"$(PODS_ROOT)/RCT-Folly\" \"$(PODS_ROOT)/DoubleConversion\" \"$(PODS_ROOT)/fast_float/include\" \"$(PODS_ROOT)/fmt/include\"",
-                               "DEFINES_MODULE" => "YES" }
+  s.pod_target_xcconfig    = {
+    "HEADER_SEARCH_PATHS" => "\"$(PODS_ROOT)/boost\" \"$(PODS_ROOT)/RCT-Folly\" \"$(PODS_ROOT)/DoubleConversion\" \"$(PODS_ROOT)/fast_float/include\" \"$(PODS_ROOT)/fmt/include\"",
+    "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
+    "DEFINES_MODULE" => "YES"
+  }
 
   s.dependency "boost"
   s.dependency "DoubleConversion"

packages/react-native/ReactCommon/react/nativemodule/defaults/React-defaultsnativemodule.podspec

@@ -16,7 +16,13 @@ else
   source[:tag] = "v#{version}"
 end
 
-header_search_paths = []
+header_search_paths = [
+  "\"$(PODS_ROOT)/RCT-Folly\"",
+]
+
+folly_config = get_folly_config()
+folly_compiler_flags = folly_config[:compiler_flags]
+folly_version = folly_config[:version]
 
 if ENV['USE_FRAMEWORKS']
   header_search_paths << "\"$(PODS_TARGET_SRCROOT)/../../..\"" # this is needed to allow the defaultsnativemodule to access its own files
@@ -31,10 +37,12 @@ Pod::Spec.new do |s|
   s.author                 = "Meta Platforms, Inc. and its affiliates"
   s.platforms              = min_supported_versions
   s.source                 = source
+  s.compiler_flags         = folly_compiler_flags
   s.source_files           = "*.{cpp,h}"
   s.header_dir             = "react/nativemodule/defaults"
   s.pod_target_xcconfig    = { "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
                                "HEADER_SEARCH_PATHS" => header_search_paths.join(' '),
+                               "OTHER_CFLAGS" => "$(inherited) " + folly_compiler_flags,
                                "DEFINES_MODULE" => "YES" }
 
   if ENV['USE_FRAMEWORKS']
@@ -42,10 +50,18 @@ Pod::Spec.new do |s|
     s.header_mappings_dir  = "../.."
   end
 
-  install_modules_dependencies(s)
+  s.dependency "RCT-Folly"
+  s.dependency "React-jsi"
+  s.dependency "React-jsiexecutor"
+  if ENV["USE_HERMES"] == nil || ENV["USE_HERMES"] == "1"
+    s.dependency "hermes-engine"
+  else
+    s.dependency "React-jsc"
+  end
 
   s.dependency "React-domnativemodule"
   s.dependency "React-featureflagsnativemodule"
   s.dependency "React-microtasksnativemodule"
   s.dependency "React-idlecallbacksnativemodule"
+  add_dependency(s, "React-RCTFBReactNativeSpec")
 end

packages/react-native/ReactCommon/react/nativemodule/dom/React-domnativemodule.podspec

@@ -16,7 +16,14 @@ else
   source[:tag] = "v#{version}"
 end
 
-header_search_paths = []
+header_search_paths = [
+  "\"$(PODS_ROOT)/RCT-Folly\"",
+  "\"$(PODS_ROOT)/Headers/Private/Yoga\"",
+]
+
+folly_config = get_folly_config()
+folly_compiler_flags = folly_config[:compiler_flags]
+folly_version = folly_config[:version]
 
 if ENV['USE_FRAMEWORKS']
   header_search_paths << "\"$(PODS_TARGET_SRCROOT)/../../..\"" # this is needed to allow the domnativemodule to access its own files
@@ -31,10 +38,12 @@ Pod::Spec.new do |s|
   s.author                 = "Meta Platforms, Inc. and its affiliates"
   s.platforms              = min_supported_versions
   s.source                 = source
+  s.compiler_flags         = folly_compiler_flags
   s.source_files           = "*.{cpp,h}"
   s.header_dir             = "react/nativemodule/dom"
   s.pod_target_xcconfig    = { "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
                                "HEADER_SEARCH_PATHS" => header_search_paths.join(' '),
+                               "OTHER_CFLAGS" => "$(inherited) " + folly_compiler_flags,
                                "DEFINES_MODULE" => "YES" }
 
   if ENV['USE_FRAMEWORKS']
@@ -42,9 +51,18 @@ Pod::Spec.new do |s|
     s.header_mappings_dir  = "../.."
   end
 
-  install_modules_dependencies(s)
-
+  s.dependency "RCT-Folly"
+  s.dependency "React-jsi"
+  s.dependency "React-jsiexecutor"
+  if ENV["USE_HERMES"] == nil || ENV["USE_HERMES"] == "1"
+    s.dependency "hermes-engine"
+  else
+    s.dependency "React-jsc"
+  end
+  s.dependency "Yoga"
   s.dependency "ReactCommon/turbomodule/core"
   s.dependency "React-Fabric"
   s.dependency "React-FabricComponents"
+  add_dependency(s, "React-graphics", :additional_framework_paths => ["react/renderer/graphics/platform/ios"])
+  add_dependency(s, "React-RCTFBReactNativeSpec")
 end

packages/react-native/ReactCommon/react/nativemodule/featureflags/React-featureflagsnativemodule.podspec

@@ -16,7 +16,13 @@ else
   source[:tag] = "v#{version}"
 end
 
-header_search_paths = []
+header_search_paths = [
+  "\"$(PODS_ROOT)/RCT-Folly\"",
+]
+
+folly_config = get_folly_config()
+folly_compiler_flags = folly_config[:compiler_flags]
+folly_version = folly_config[:version]
 
 if ENV['USE_FRAMEWORKS']
   header_search_paths << "\"$(PODS_TARGET_SRCROOT)/../../..\"" # this is needed to allow the feature flags access its own files
@@ -31,10 +37,12 @@ Pod::Spec.new do |s|
   s.author                 = "Meta Platforms, Inc. and its affiliates"
   s.platforms              = min_supported_versions
   s.source                 = source
+  s.compiler_flags         = folly_compiler_flags
   s.source_files           = "*.{cpp,h}"
   s.header_dir             = "react/nativemodule/featureflags"
   s.pod_target_xcconfig    = { "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
                                "HEADER_SEARCH_PATHS" => header_search_paths.join(' '),
+                               "OTHER_CFLAGS" => "$(inherited) " + folly_compiler_flags,
                                "DEFINES_MODULE" => "YES" }
 
   if ENV['USE_FRAMEWORKS']
@@ -42,7 +50,15 @@ Pod::Spec.new do |s|
     s.header_mappings_dir  = "../.."
   end
 
-  install_modules_dependencies(s)
-
+  s.dependency "RCT-Folly"
+  s.dependency "React-jsi"
+  s.dependency "React-jsiexecutor"
+  if ENV["USE_HERMES"] == nil || ENV["USE_HERMES"] == "1"
+    s.dependency "hermes-engine"
+  else
+    s.dependency "React-jsc"
+  end
   s.dependency "ReactCommon/turbomodule/core"
+  s.dependency "React-RCTFBReactNativeSpec"
+  s.dependency "React-featureflags"
 end

packages/react-native/ReactCommon/react/nativemodule/idlecallbacks/React-idlecallbacksnativemodule.podspec

@@ -16,7 +16,13 @@ else
   source[:tag] = "v#{version}"
 end
 
-header_search_paths = []
+header_search_paths = [
+  "\"$(PODS_ROOT)/RCT-Folly\"",
+]
+
+folly_config = get_folly_config()
+folly_compiler_flags = folly_config[:compiler_flags]
+folly_version = folly_config[:version]
 
 if ENV['USE_FRAMEWORKS']
   header_search_paths << "\"$(PODS_TARGET_SRCROOT)/../../..\"" # this is needed to allow the module access its own files
@@ -31,10 +37,12 @@ Pod::Spec.new do |s|
   s.author                 = "Meta Platforms, Inc. and its affiliates"
   s.platforms              = min_supported_versions
   s.source                 = source
+  s.compiler_flags         = folly_compiler_flags
   s.source_files           = "*.{cpp,h}"
   s.header_dir             = "react/nativemodule/idlecallbacks"
   s.pod_target_xcconfig    = { "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
                                "HEADER_SEARCH_PATHS" => header_search_paths.join(' '),
+                               "OTHER_CFLAGS" => "$(inherited) " + folly_compiler_flags,
                                "DEFINES_MODULE" => "YES" }
 
   if ENV['USE_FRAMEWORKS']
@@ -42,8 +50,15 @@ Pod::Spec.new do |s|
     s.header_mappings_dir  = "../.."
   end
 
-  install_modules_dependencies(s)
-
+  s.dependency "RCT-Folly"
+  s.dependency "React-jsi"
+  s.dependency "React-jsiexecutor"
+  if ENV["USE_HERMES"] == nil || ENV["USE_HERMES"] == "1"
+    s.dependency "hermes-engine"
+  else
+    s.dependency "React-jsc"
+  end
   s.dependency "ReactCommon/turbomodule/core"
   s.dependency "React-runtimescheduler"
+  add_dependency(s, "React-RCTFBReactNativeSpec")
 end

packages/react-native/ReactCommon/react/nativemodule/microtasks/React-microtasksnativemodule.podspec

@@ -16,7 +16,13 @@ else
   source[:tag] = "v#{version}"
 end
 
-header_search_paths = []
+header_search_paths = [
+  "\"$(PODS_ROOT)/RCT-Folly\"",
+]
+
+folly_config = get_folly_config()
+folly_compiler_flags = folly_config[:compiler_flags]
+folly_version = folly_config[:version]
 
 if ENV['USE_FRAMEWORKS']
   header_search_paths << "\"$(PODS_TARGET_SRCROOT)/../../..\"" # this is needed to allow the microtasks module access its own files
@@ -31,9 +37,11 @@ Pod::Spec.new do |s|
   s.author                 = "Meta Platforms, Inc. and its affiliates"
   s.platforms              = min_supported_versions
   s.source                 = source
+  s.compiler_flags         = folly_compiler_flags
   s.source_files           = "*.{cpp,h}"
   s.header_dir             = "react/nativemodule/microtasks"
   s.pod_target_xcconfig    = { "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
+                               "OTHER_CFLAGS" => "$(inherited) " + folly_compiler_flags,
                                "HEADER_SEARCH_PATHS" => header_search_paths.join(' '),
                                "DEFINES_MODULE" => "YES" }
 
@@ -42,7 +50,14 @@ Pod::Spec.new do |s|
     s.header_mappings_dir  = "../.."
   end
 
-  install_modules_dependencies(s)
-
+  s.dependency "RCT-Folly"
+  s.dependency "React-jsi"
+  s.dependency "React-jsiexecutor"
+  if ENV["USE_HERMES"] == nil || ENV["USE_HERMES"] == "1"
+    s.dependency "hermes-engine"
+  else
+    s.dependency "React-jsc"
+  end
   s.dependency "ReactCommon/turbomodule/core"
+  add_dependency(s, "React-RCTFBReactNativeSpec")
 end

packages/react-native/ReactCommon/react/nativemodule/samples/ReactCommon-Samples.podspec

@@ -69,9 +69,9 @@ Pod::Spec.new do |s|
   s.dependency "React-Core"
   s.dependency "React-cxxreact"
   s.dependency "React-jsi"
-  add_dependency(s, "ReactCodegen", :additional_framework_paths => ["build/generated/ios"])
+  add_dependency(s, "React-RCTFBReactNativeSpec")
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])
-  add_dependency(s, "React-NativeModulesApple", :additional_framework_paths => ["build/generated/ios"])
+  add_dependency(s, "React-NativeModulesApple")
 
   if using_hermes
     s.dependency "hermes-engine"

packages/react-native/ReactCommon/react/runtime/platform/ios/React-RuntimeApple.podspec

@@ -71,7 +71,7 @@ Pod::Spec.new do |s|
   s.dependency "React-jsinspector"
   s.dependency "React-featureflags"
 
-  add_dependency(s, "ReactCodegen")
+  add_dependency(s, "React-RCTFBReactNativeSpec")
 
   if ENV["USE_HERMES"] == nil || ENV["USE_HERMES"] == "1"
     s.dependency "hermes-engine"

packages/react-native/scripts/codegen/generate-artifacts-executor.js

@@ -47,7 +47,11 @@ const RNCORE_CONFIGS = {
 const CORE_LIBRARIES_WITH_OUTPUT_FOLDER = {
   rncore: RNCORE_CONFIGS,
   FBReactNativeSpec: {
-    ios: null,
+    ios: path.join(
+      REACT_NATIVE_PACKAGE_ROOT_FOLDER,
+      'React',
+      'FBReactNativeSpec',
+    ),
     android: path.join(
       REACT_NATIVE_PACKAGE_ROOT_FOLDER,
       'ReactAndroid',
@@ -451,13 +455,7 @@ function shouldSkipGenerationForRncore(schemaInfo, platform) {
   if (platform !== 'ios' || schemaInfo.library.config.name !== 'rncore') {
     return false;
   }
-  const rncoreOutputPath = path.join(
-    RNCORE_CONFIGS.ios,
-    'react',
-    'renderer',
-    'components',
-    'rncore',
-  );
+  const rncoreOutputPath = CORE_LIBRARIES_WITH_OUTPUT_FOLDER.rncore.ios;
   const rncoreAbsolutePath = path.resolve(rncoreOutputPath);
   return (
     rncoreAbsolutePath.includes('node_modules') &&
@@ -466,6 +464,26 @@ function shouldSkipGenerationForRncore(schemaInfo, platform) {
   );
 }
 
+function shouldSkipGenerationForFBReactNativeSpec(schemaInfo, platform) {
+  if (
+    platform !== 'ios' ||
+    schemaInfo.library.config.name !== 'FBReactNativeSpec'
+  ) {
+    return false;
+  }
+
+  const fbReactNativeSpecOutputPath =
+    CORE_LIBRARIES_WITH_OUTPUT_FOLDER.FBReactNativeSpec.ios;
+  const fbReactNativeSpecAbsolutePath = path.resolve(
+    fbReactNativeSpecOutputPath,
+  );
+  return (
+    fbReactNativeSpecAbsolutePath.includes('node_modules') &&
+    fs.existsSync(fbReactNativeSpecAbsolutePath) &&
+    fs.readdirSync(fbReactNativeSpecAbsolutePath).length > 0
+  );
+}
+
 function generateCode(outputPath, schemaInfo, includesGeneratedCode, platform) {
   if (shouldSkipGenerationForRncore(schemaInfo, platform)) {
     codegenLog(
@@ -475,6 +493,14 @@ function generateCode(outputPath, schemaInfo, includesGeneratedCode, platform) {
     return;
   }
 
+  if (shouldSkipGenerationForFBReactNativeSpec(schemaInfo, platform)) {
+    codegenLog(
+      '[Codegen - FBReactNativeSpec] Skipping iOS code generation for FBReactNativeSpec as it has been generated already.',
+      true,
+    );
+    return;
+  }
+
   const libraryName = schemaInfo.library.config.name;
   const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), libraryName));
   const tmpOutputDir = path.join(tmpDir, 'out');
@@ -615,6 +641,8 @@ function generateCustomURLHandlers(libraries, outputDir) {
     .replace(/{imageDataDecoderClassNames}/, customImageDataDecoderClasses)
     .replace(/{requestHandlersClassNames}/, customURLHandlerClasses);
 
+  fs.mkdirSync(outputDir, {recursive: true});
+
   fs.writeFileSync(
     path.join(outputDir, 'RCTModulesConformingToProtocolsProvider.mm'),
     finalMMFile,
@@ -676,6 +704,23 @@ function generateRNCoreComponentsIOS(projectRoot /*: string */) /*: void*/ {
   generateCode('', rncoreSchemaInfo, false, ios);
 }
 
+function generateFBReactNativeSpecIOS(projectRoot /*: string */) /*: void*/ {
+  const ios = 'ios';
+  buildCodegenIfNeeded();
+  const pkgJson = readPkgJsonInDirectory(projectRoot);
+  const fbReactNativeSpecLib = findProjectRootLibraries(
+    pkgJson,
+    projectRoot,
+  ).filter(library => library.config.name === 'FBReactNativeSpec')[0];
+  if (!fbReactNativeSpecLib) {
+    throw new Error(
+      "[Codegen] Can't find FBReactNativeSpec library. Failed to generate rncore artifacts",
+    );
+  }
+  const fbReactNativeSchemaInfo = generateSchemaInfo(fbReactNativeSpecLib, ios);
+  generateCode('', fbReactNativeSchemaInfo, false, ios);
+}
+
 // Execute
 
 /**
@@ -773,6 +818,7 @@ function execute(projectRoot, targetPlatform, baseOutputPath) {
 module.exports = {
   execute,
   generateRNCoreComponentsIOS,
+  generateFBReactNativeSpecIOS,
   // exported for testing purposes only:
   _extractLibrariesFromJSON: extractLibrariesFromJSON,
   _cleanupEmptyFilesAndFolders: cleanupEmptyFilesAndFolders,

packages/react-native/scripts/prepack.js

@@ -10,6 +10,7 @@
  */
 
 const {
+  generateFBReactNativeSpecIOS,
   generateRNCoreComponentsIOS,
 } = require('./codegen/generate-artifacts-executor');
 const fs = require('fs');
@@ -18,6 +19,7 @@ function main() {
   console.info('[Prepack] Copying README.md');
   fs.copyFileSync('../../README.md', './README.md');
   generateRNCoreComponentsIOS('.');
+  generateFBReactNativeSpecIOS('.');
 }
 
 if (require.main === module) {

packages/react-native/scripts/react_native_pods.rb

@@ -130,6 +130,7 @@ def use_react_native! (
   pod 'React-jserrorhandler', :path => "#{prefix}/ReactCommon/jserrorhandler"
   pod 'React-nativeconfig', :path => "#{prefix}/ReactCommon"
   pod 'RCTDeprecation', :path => "#{prefix}/ReactApple/Libraries/RCTFoundation/RCTDeprecation"
+  pod 'React-RCTFBReactNativeSpec', :path => "#{prefix}/React"
 
   if hermes_enabled
     setup_hermes!(:react_native_path => prefix)